1. Field of the Invention
The invention relates to a key cylinder device.
2. Description of the Related Art
An example of key cylinder devices known is a cylinder lock for locking and unlocking a door lock mechanism equipped in a vehicle door see e.g. JP-A-2014-177802).
JP-A-2014-177802 discloses a cylinder lock that is provided with inner and outer cylinders. The inner cylinder has a keyhole into which a mechanical key is inserted. The outer cylinder encloses the inner cylinder to be relatively rotatably inserted and held, and is rotatably held by a fixed housing.
The inner cylinder is provided with half tumblers which can be engaged with the outer cylinder and disengaged from the outer cylinder upon insertion of the mechanical key into the keyhole.
The outer cylinder is provided with two pairs of engaging grooves at an inner periphery thereof which extend along an axial direction and sandwich a dividing wall therebetween. The half tumblers are biased by a spring toward a side where they are engaged with the two pairs of engaging grooves.
When the mechanical key is not inserted into the keyhole of the inner cylinder, the half tumblers are engaged with the engaging grooves of the outer cylinder. When the mechanical key is inserted into the keyhole, the half tumblers are disengaged from the engaging grooves of the outer cylinder.